Dysregulated Polycomb Repressive Complex 2 contributes to chronic obstructive pulmonary disease by rewiring stem cell fate.

Aberrant lung cell differentiation is a hallmark of many lung diseases including chronic obstructive pulmonary disease (COPD). The EZH2-containing Polycomb Repressive Complex 2 (PRC2) regulates embryonic lung stem cell fate, but its role in adult lung is obscure. Histological analysis of patient tissues revealed that loss of PRC2 activity was correlated with aberrant bronchiolar cell differentiation in COPD lung. Histological and single-cell RNA-sequencing analyses showed that loss of EZH2 in mouse lung organoids led to lowered self-renewal capability, increased squamous morphological development, and marked shifts in progenitor cell populations. Evaluation of in vivo models revealed that heterozygosity of Ezh2 in mice with ovalbumin-induced lung inflammation led to epithelial cell differentiation patterns similar to those in COPD lung. We also identified cystathionine-ß-synthase as a possible upstream factor for PRC2 destabilization. Our findings suggest that PRC2 is integral to facilitating proper lung stem cell differentiation in humans and mice.

Quaternary Structure and Deoxyribonucleic Acid-Binding Properties of the Heme-Dependent, CO-Sensing Transcriptional Regulator PxRcoM.

RcoM, a heme-containing, CO-sensing transcription factor, is one of two known bacterial regulators of CO metabolism. Unlike its analogue CooA, the structure and DNA-binding properties of RcoM remain largely uncharacterized. Using a combination of size exclusion chromatography and sedimentation equilibrium, we demonstrate that RcoM-1 from Paraburkholderia xenovorans is a dimer, wherein the heme-binding domain mediates dimerization. Using bioinformatics, we show that RcoM is found in three distinct genomic contexts, in accordance with the previous literature. We propose a refined consensus DNA-binding sequence for RcoM based on sequence alignments of coxM-associated promoters. The RcoM promoter consensus sequence bears two well-conserved direct repeats, consistent with other LytTR domain-containing transcription factors. In addition, there is a third, moderately conserved direct repeat site. Surprisingly, PxRcoM-1 requires all three repeat sites to cooperatively bind DNA with a [P]1/2 of 250 ± 10 nM and an average Hill coefficient, n, of 1.7 ± 0.1. The paralog PxRcoM-2 binds to the same triplet motif with comparable affinity and cooperativity. Considering this unusual DNA binding stoichiometry, that is, a dimeric protein with a triplet DNA repeat-binding site, we hypothesize that RcoM interacts with DNA in a manner distinct from other LytTR domain-containing transcription factors.

Assessing the Intention, Attitudes, and Social Influences on COVID-19 Preventive Behaviors Among Non-rural Black and Rural Appalachian White Populations: A Faith-Based Community Study.

Introduction: The COVID-19 pandemic has had detrimental impacts in non-rural Black and rural Appalachian populations. Yet despite the pandemic's magnitude, there is a scarcity of research exploring potential influences of attitudes and social influences within these populations on their adherence to COVID-19 public health preventive behaviors. Purpose: This study examines the intention, attitudes, and social influences to adhere to COVID-19 preventive behaviors among non-rural Black and rural Appalachian congregants in Kentucky by integrating the Theory of Planned Behavior (TPB). Methods: Secondary analysis of cross-sectional data was used to assess the association between the TPB constructs and four key public health behaviors: obeying a stay-at-home order, social distancing, good hygiene practices, and wearing a mask in public. Generalized estimating equation-type logistic regression models were fit for all binary outcomes. Results: A total of 942 respondents completed the survey. Eighty-nine per cent were older than 36 years, and 73% were female. Of the respondents who were White, 97.7% lived in rural Appalachia Kentucky, and of those who were Black, 93.5% lived in non-rural Kentucky. Attitude towards the behavior was negatively associated with the stay-at-home order ( p=0.003). Both attitude toward the behavior ( p<0.001) and the subjective norm ( p=0.025) were negatively associated with mask wearing. Perceived behavioral control was positively associated with mask wearing ( p=0.023) with non-rural respondents more likely to wear a mask than rural ones ( p<0.001). None of the TPB constructs showed significant association with hygiene practices or with social distancing. Implications: This study provides further insight into the cultural and societal influences that intersect during a global pandemic. The intention to comply with public health recommendations may vary at favorable and unfavorable levels. The results lend support to the importance of designing effective, culturally tailored communication for future public health preparedness.

COVID-19 and the impact on rural and black church Congregants: Results of the C-M-C project.

The COVID-19 pandemic has had devastating effects on Black and rural populations with a mortality rate among Blacks three times that of Whites and both rural and Black populations experiencing limited access to COVID-19 resources. The primary purpose of this study was to explore the health, financial, and psychological impact of COVID-19 among rural White Appalachian and Black nonrural central Kentucky church congregants. Secondarily we sought to examine the association between sociodemographics and behaviors, attitudes, and beliefs regarding COVID-19 and intent to vaccinate. We used a cross sectional survey design developed with the constructs of the Health Belief and Theory of Planned Behavior models. The majority of the 942 respondents were ≥36 years. A total of 54% were from central Kentucky, while 47.5% were from Appalachia. Among all participants, the pandemic worsened anxiety and depression and delayed access to medical care. There were no associations between sociodemographics and practicing COVID-19 prevention behaviors. Appalachian region was associated with financial burden and delay in medical care (p = 0.03). Appalachian respondents had lower perceived benefit and attitude for COVID-19 prevention behaviors (p = 0.004 and <0.001, respectively). Among all respondents, the perceived risk of contracting COVID was high (54%), yet 33.2% indicated unlikeliness to receive the COVID-19 vaccine if offered. The COVID-19 pandemic had a differential impact on White rural and Black nonrural populations. Nurses and public health officials should assess knowledge and explore patient's attitudes regarding COVID-19 prevention behaviors, as well as advocate for public health resources to reduce the differential impact of COVID-19 on these at-risk populations.

Met(104) is the CO-replaceable ligand at Fe(II) heme in the CO-sensing transcription factor BxRcoM-1.

Both Met(104) and Met(105) are involved, either directly or indirectly, in the redox mediated ligand switch of the heme-dependent transcription factor, RcoM-1. Recent studies of Burkholderia xenovorans RcoM identified Cys(94) as the thiolate ligand in the Fe(III) state of the heme cofactor. Upon reduction, a neutral donor replaces Cys(94) trans to His(74). Homology modelling implicated either Met(104) or Met(105) as the possible ligand in the Fe(II) state. We spectroscopically compared wild type (WT) RcoM-1 to three Met-to-Leu variants (M104L, M105L, and M104L/M105L) to identify which Met residue acts as the ligand. All proteins were isolated as admixtures of Fe(III) and Fe(II)-CO heme; oxidation by ferricyanide enables study of homogeneous oxidation and coordination states. Met(104) is the CO-replaceable Fe(II) heme ligand. The magnetic circular dichroism (MCD) spectrum of Fe(II) M105L resembled WT. M104L and M104L/M105L, however, showed spectra arising from the formation of a high-spin, five-coordinate species indicating the loss of the ligand. The electron paramagnetic resonance (EPR) spectra of WT Fe(III) RcoM-1, oxidized Fe(III) M104L, and as-isolated M105L exhibited narrow, rhombic low-spin signals typical of thiolate-bound hemes. In contrast, oxidized Fe(III) M105L and oxidized Fe(III) M104L/M105L revealed a broad, rhombic low-spin, six-coordinate signal indicative of replacement of the thiolate by a neutral ligand. Thus, we conclude that Met(105) is important to the stability of the Fe(III) heme pocket during oxidation.